Apparatus for slitting sheet material



July 10, 1962 A. L. WORRALL, JR

APPARATUS FOR SLITTING SHEET MATERIAL 6 Sheets-Sheet 1 Filed April 6, 1960 W MW ATTYS.

July 10, 1962 A. L. WORRALL, JR 3, 4

APPARATUS FOR SLITTING SHEET MATERIAL Filed April 6. 1960 e Sheets-Sheet 2 INVENTOR. ASHTON LWORRALL JR.

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APPARATUS FOR sumac SHEET MATERIAL 6 Sheets-Sheet 4 Filed April 6, 1960 INVENTOR.

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A. L. WORRALL, JR I APPARATUS FOR SLITTING SHEET MATERIAL July 10, 1962 6 Sheets-Sheet 5 Filed-April 6. 1960 QUE INVENTOR. ASHTON LWORRALLJR.

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July 10, 1962 A. WORRALL, JR

APPARATUS FOR SLITTING SHEET MATERIAL 6 Sheets-Sheet 6 Filed April 6, 1960 1 A W a \1, 8 H km- W NR W I F AHI| H H m M HII H m mm w o o INVENTOR. ASHTON L.WORRALL JR finite hrates Patented July 10, 1962 e Ii This invention relates to apparatus for slitting sheet material and is especially useful where a sheet of material or a tubular body thereof is to be slit to provide a series of strips or bands of uinform width.

In the manufacture of strip material from a sheet thereof it has been proposed to pass the sheet material past a multiplicity of evenly spaced cutting blades to simultaneously divide the sheet into a multiplicity of narrow bands or tapes of uniform width. Such devices have not been entirely satisfactory as the knives soon dull from constant application to the material and replacing the blades or adjusting them to different spacing has required considerable waste of time. Also, in such devices the sheet material has tended to be deflected laterally by the blades so that the tapes produced were not straight and the power necessary to move the sheet material over the blades has been excessive due to dulling of the blades, crowding of the tapes between the blades and the necessity of simultaneously cutting with all of the blades.

In the manufacture of endless belts of rubber and cord or fabric it has been proposed to wind the materials. to form a tubular body, to mount the tubular body about an expandable rubber cushion faced drum, to rotate the drum and the tubular body, and to successively feed a knife blade radially through the tubular body at spaced intervals to divide it into narrow bands. Such a procedure has been quite slow and widths of the bands have not been uniform due to lateral shifting of the tubular material due to side thrust.

In an effort to conserve time, it has been proposed to simultaneously feed a multiplicity of blades through the tubular body of material While rotating the body. This has been found to require an excessive amount of power, to increase the tendency of the tubular body to slip relative to the mandrel and to require too much time in adjusting the blades to different spacing.

The present invention aims to overcome the foregoing and other difliculties.

It is an object of the present invention to provide for presenting in succession at a cutting station, groups of determinately spaced cutting blades and to provide means at such station for advancing the blades so presented through the material to slit the material into bands of determinate width.

It is a further object to provide for mounting the groups of determinately spaced cutting blades on laterally exteuding supporting bars of a rotatable cage or turret and to provide means at a cutting station to advance the blades of one supporting bar through the material to be cut.

It is a still further object to provide rotative travel of the cage or turret supported bars about the blade-advancing mechanism.

It is another object of the invention to provide such apparatus in which the means for advancing the blades supported by one laterally extending bar is adapted to advance the blades in successive groups of blades and to so advance the blades that one group enters the material before the preceding group is entirely withdrawn from the material.

It is another object of the invention to provide such an apparatus in which the blade-supporting bars may be readily removed and replaced.

Still another object is to provide a series of turret supported bars in which each bar has a multiplicity of blade supporting holders and the blades of different supporting bars are arranged in different spaced relation for cutting stripes of different widths.

Another object is to provide each blade holder with individual retracting means.

Yet a further object is to provide for adjustment of cutting edges of the blades.

Another object is to provide means for successively I advancing through the material in overlapping advancing movements a plurality of groups of spaced blades from a single indexing position of a cage or turret sup porting the blades.

Another object is to provide cage or turret means for rotatably indexing axially spaced groups of blade holders into and out of cutting position past blade holder group advancing means and to provide overlapping step by step advance of said groups by means located said turret means.

These and other objects will appear from the following description and the accompanying drawings.

Of the drawings:

FIG. 1 is a plan view of one form of apparatus embodying the invention only one of the bars being shown as supporting blades, the others being omitted for simplicity.

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1 showing the turret or reel, the cam and pusher bar mechanism.

FIG. 3 is a front face view of a portion of the pusher bar support taken on line 3-3 of FIG. 2 showing one of the pusher bars and its guide in section, on line 33zz, portions being broken away.

FIG. 4 is a plan view of a portion of the pusher bar support and two of the pusher bars, taken on line 44 of FIG. 2.

FIG. 5 is a plan view of a portion of one of the knife supporting bars and two of the knife supporting blocks, other portions being broken away.

FIG. 6 is a side view of one of the knife supporting blocks.

FIG. 7 is a face view thereof.

FIG. 8 is a side view of the cam shaft and its driving mechanism, parts being broken away.

FIG. 9 is a cross-sectional end view thereof taken on line 99 of FIG. 8, the pusher rod and its guide being shown with the supporting bar in section.

FIG. 10 is a top plan view of the apparatus of FIG. 1 partly in section.

In the embodiment of the invention shown the cutter supporting bars are mounted for quick change about a turret or cage whereby quick indexing of a balanced arrangement of blade supports is provided for quick change with a minimum of efiort. Also in order to provide positive advance of the groups of blades in determinate arrangement and to supply a large number of blade spacings about a single turret of minimum size, the turret is arranged to revolve about a geometric center by guides engaging end rings of the turret or cage, leaving open space throughout the turret for mounting the knife operating mechanism.

Referring to FIGS. 1 to 10 inclusive, a frame is pro- 'vided having parallel side walls 30, 31. A p'ush rod support bar 32 extends between the side walls and its ends are secured thereto. A reel 33 is provided for rotation about a geometric center between the side walls and about the bar 32. The reel comprises a pair of end rings 34, 35 about which are removably secured a multiplicity of cutter supporting bars 36 in parallel spaced apart relation.

For rotatably guiding and supporting the reel 33, a

contacting end faces of the rings.

plurality of roller brackets 37 are secured to end walls 34, and each has a roller 38 with its periphery tangent to the periphery of the end rings. Other roller brackets 39 are mounted on the side walls and have rollers 40 for The arrangement is such that the reel is supported and guided by its end j'rings leaving the ends of the reel open toclear the bar 32 and the cam shaft.

Eachcutter supporting bar 36 seats at its ends in notches 41 of the rings and is held in place by a locating dowel pin 42 at each end and screws 43 for removal and replacement.

Mounted on the supporting bar 32 in spaced apart parallel horizontal relation are a number of cylindrical guides 44, each having a bore 45 for guiding a push rod 46. Each push rod supports a cam-engaging roller 47 at one end'thereof and a knife-block engaging roller 43 at its opposite end. .Each guide 44 (see FIG. 3) has a longitudinal slot 49 communicating with its bore and a guide pin 50 is mounted on the push rod and extends through the slot 49 to limit movement of the push rod and to prevent its rotation. For resisting movement of the push rod toward a knife block, a pair of extension coil springs 51. (FIG. 4) are provided at each guide 44 i with one end of the spring anchored at a pin 52 to the guide 44 and the other end anchored to the push rod 46 at' a roller pin 53. Rotatably journalled in bearings 53 (FIG. 8) secured to side walls 30, 31 with its axis parallel to the axis of rotation of the cage 33 is a cam shaft 54. A sprocket 55 is mounted on the cam shaft and isadapted to be driven by a chain 56 from any convenient source of power such as a motor 57. Mounted on the cam shaft, as by keys 58, are a series of earns 59, one for each push rod 46. Each cam is adapted to contact a push rod during its revolution throughout an angle of about 70 degrees, ad-

vancing the push rod then holding it advanced throughout an angle of about 14 degrees and then releasing it.

for. return by its springs. The cams are progressively set, usually in pairs as shown, at angular spacings along the cam shaft so as toengage and advance the push rods in succession and to hold one pair of push rods advanced while the succeeding push rod is being advanced. In a position where all of the cams release the push rods (see blank area of cams 59 in FIG. 3) .the springs 51 will retract the rods 46 to positions clearing the support bars '36 and will allow rotation of the turret 33 and the loading and unloading of the drum 86.

For pivotally supporting cutting blades from each bar f36'a number of blade carriers 64 (FIGS. 1, 6 and 7) are provided.

Each" blade carrier may conveniently comprise a hanger bar 65 having a pair of hinge cars 66 for 'pivotally mounting the carrier to a bar, 36, a backing block 67 secured at one edge by screws68 to the hanger 65, and a plate clamping jaw 69 secured by' screws 70 to the opposite edge of'the block 67. A set of spacing clearance openings in the spacer blocks and slots 78 in the blades to clamp the blades in place. By changing the spacer blocks, any desired blade spacing may be provided. The entire assembly of the carrier is mounted for hinging on a hinge pin 80 carried by a hanger 31 mounted on the bar 36 between its ears, all of the hinge pins be-. ing in alignment along the bar and being in shoulder to shoulder relation. 7

In advancing the blade carriers 64, the roller 48 of one of the push rods 46 engages the rear surface of the backing block 67 by advancing through the space between adjacent bars 36. A torsion coil spring 91 about the hinge pin of each blade carrier normally holds the blade carrier in retracted position. a

'of blocks for another.

The mounting of the blade carriers on removable bars 36 makes possible quick substitution of one row or set The mounting of the bars about a cage and operation of the block hangers by mechanism mounted within the cage makes possible the mounting of a great many rows of blade carriers about the cage.

Change of cutting blades ordinarily is accomplished by rotation of the cage to bring the desired row of blade carriers in position at the push rods. For locking the cage 33 an indexing detent 82 (FIG. 2) is slidably mounted in a guideway 83 mounted on the side wall 31. The detent is adapted to engage index sockets in end ring 35. A spring 84 holds the pin in the socket but may be depressed by withdrawing the pin to permit rotation of the cage.

A rotatable drum 86 .is rotatably mounted on extensions of frame side walls 30 and 31 for supporting the material to be cut which is usually in'the form of an endless band 88. The drum has a soft rubber face 87 adapted to permit advance of the cutting blades thereinto without injury to the blades. The drum 86 is rotatably driven in the direction of the arrow by the motor 90. (FIG. 10). As will be seen in FIG. 2, each row of blades is pivoted at a position below a plane intersecting the axes of the cage 33 and the drum 86 and the blades are inclined with their most advanced corners above such a plane so that the blades enter the material to be cut substantially tangent thereto providing a draw cut.

The work supporting drum and the blade supporting mechanism including the cage may be mounted for movement of one toward the other if desired.

Due to the mounting of the blades on pivoted supports and the progressive arrangement of the operating cams and push rods, the blades of a row are advanced into the work in a succession of groups of blades and by so shaping the cams, one group of blades may be entered in the work before the preceding group is entirely withdrawn therefrom so that one group of blades in the material steadies the work and assures entry of the next group in properly spaced relation with the first. Such a procedure greatly reduces the amount of energy required to" rotate the work supporting drum.

belt or other material to be cut into narrow endless bands is trained about supporting drum 86 provided with a rubber or other surface into which blades may be advanced.

Locking detent pin 82 is released and the cage 33 rotated if necessary to a position Where cutting blades of the desired spacing are in line with the push rods 14 or 46. The cage is locked by releasing the detent. Thereafter the cam shaft 54 is rotated to progressively advance groups of the blades of a row'while at the same time the drum is rotated in the direction of the arrow to advance the work past the blades.

While certain representative embodiments and details have been shown in order to illustrate the invention, it

' will be. apparent to those skilled in the art that various comprising; a frame means; a cushion faced, material supporting and advancing drum mounted on said frame means; a rotatable cagesupporting a plurality of rows of spaced apart cutting blades on said frame means adjacent said drum, the area of adjacency of said drum and 5. said cage defining a cutting station, each of said rows being presentable one at a time at said cutting station, pivotally mounting the individual blades of each row in groups on said' cage, means for locking said cage against rotation with one row at a cutting station adjacent said drum, and means at said cutting station for pivotally advancing said groups of blades in succession through the material about said drum.

2. Apparatus for slitting an endless band of material comprising; a frame means; a cushion faced, material supporting and advancing drum mounted on said frame means; a rotatable cage supporting a plurality of rows of spaced apart cutting blades on said frame means adjacent said drum, the area of adjacency of said drum and said cage defining a cutting station, each of said rows being presentable one at a time at said cutting station; a removable supporting bar pivotally mounting the individual blades of each row in groups on said cage; means for locking said cage against rotation with one row at a cutting station adjacent said drum; and means at said cutting station for pivotally advancing said groups of blades in succession through the material about said drum, said last said means comprising a rotatable cam shaft having a cam for advancing each group of blades, and a push rod for transmitting motion from each cam to said group of blades.

3. Apparatus for slitting an endless band of material comprising; a frame means; a cushion faced, material supporting and advancing drum mounted on said frame means; a rotatable cage supporting a plurality of rows of spaced apart cutting blades on said frame means adjacent said drum, the area of adjacency of said drum and said cage defining a cutting station, each of said rows being presentable one at a time at said cutting station; a removable supporting bar pivotally mounting the individual blades of each row in groups on said cage; means for locking said cage against rotation with one row at a cutting station adjacent said drum, and means at said cutting. station for pivotally advancing said groups of blades in succession through the material about said drum, said last said means comprising a rotatable cam shaft having a cam for advancing each group of blades, and a push rod for transmitting motion from each cam to said group of blades, and each group of pivotally mounted blades comprising a pivoted holder and interchangeable spacer blocks and blades for mounting thereon.

4. Apparatus for slitting an endless band of material comprising; a frame means; a cushion faced, material supporting and advancing drum mounted on said frame means; a rotatable cage supporting a plurality of rows of spaced apart cutting blades on said frame means adjacent said drum, the area of adjacency of said drum and said cage defining a cutting station, each of said rows being presentable one at a time at said cutting station; means pivotally mounting the individual blades of each row on said cage; and means located within said cage for advancing the blades of each row in a determinate order to the said drum, said last mentioned means comprising a set of push rods aligned with a row of said blades at said cutting station, and a cam means aligned with said push rods for advancing said push rods and said blades in a determinate order.

References Cited in the file of this patent UNITED STATES PATENTS Hohl Mar. 19, 1957 

